The present invention relates to a method for recording data to a disk as well as to a disk recording apparatus for recording data based on that method.
In setups where data are written to a disk using a plurality of beams, data may be written to an unrecorded region that is scanned immediately before a given location where data have already been written by means of a beam. In such cases, it is preferred, for the purpose of recording data at high density with high precision, to write the data in such a manner that the end of the data to be written to the unrecorded region continues seamlessly and in a non-overlapping fashion to the beginning of the data in the ensuing recorded region.
Conventionally, however, it has been very difficult to match precisely on the disk the start of the data in any recorded region with the end of data to be recorded to an unrecorded region preceding that region.
At present, position data superposed on the wobbling grooves on the disk are read for use in determining where unrecorded regions exist on the disk surface. The retrieval of such position data allows for about a 10-percent read error, which does not contribute to improving accuracy.
Where the end of the data to be recorded is adjusted for data region coincidence on the basis of the position data mentioned above, any failure to read the position data correctly can result in a data overlap or a data gap with regard to the beginning of the data in recorded regions. The data overlap destroys what is already written in recorded regions. Both the data overlap and the data gap deviate from criteria for recording data properly to the disk and thereby incur the risk of failing to read data correctly from the disk.
If special regions called link regions are established between each recorded region and an unrecorded region, the data retrieved from the link regions during data read operations are regarded as unreliable and thus are not used. As a result, a significant amount of recording capacity is lost, much to the detriment of actually writing data to the disk.